Nonhuman primates are important animal models of human disease and are used extensively in biomedical research. Responses to treatments and experimental procedures are affected by the nutritional appropriateness and adequacy of diets being fed to nonhuman primates. Unrecognized dietary variations or inadequacies can thus result in erroneous experimental conclusions, making it difficult to reproduce results and compare data among laboratories. Awareness of biologic and physiologic characteristics of primates, such as differences in digestive strategies and metabolism, and general considerations for feeding, diet formulation, nutrient compositions of feeds, and dietary manipulation as a mechanism of environmental enrichment, can facilitate experimental design and enhance research efforts. To provide up-to-date information, the Committee on Animal Nutrition, a standing committee of the NRC Board on Agriculture, proposes to convene a subcommittee comprising twelve experts in disciplines including primate nutrition, energetics, reproductive physiology, behavior, field biology, and other fields to revise the 1978 publication, "Nutrient Requirements of Nonhuman Primates." Much new information has been published since 1978. It is anticipated that four meetings will be held over a 36-month period, and during that time, the subcommittee will review the world literature on primate nutrition and produce a report that summarizes and evaluates current knowledge on nutrient needs of nonhuman primates. The staff officer will assist the subcommittee in all phases of the project. The report will be subject to NRC review procedures and will be distributed to the public by the National Academy Press.